first question:

The accompanying frequency distribution summarizes Age (years) Number sample data consisting of ages of randomly selected 16-25 12 inmates in federal prisons. Use the data to construct a 26-35 62 95% confidence interval estimate of the mean age of all 36-45 66 inmates in federal prisons. 46-55 37 56-65 15 Over 65 4 . . . Using the class limits of 66-75 for the "over 65" group, find the confidence interval.